they don't want north korea to become a nuclear state t that's a matter obama sdaufd with his chinese, japanese and south korean counterparts on thursday-- discussed. some say the admission strayings has-- administration has tried to choose between proliferation. >> it is found in far more states than states with nuclear weapons. 24 countries have material that could be used for a nuclear weapon. what president obama did was really elevates political attention to these materials and provide political momentum them for securing them and ideally eliminating the materials. >> reporter: this is the final summit of its kind. what happens now? >> today we agreed to maintain a strong architecture, through various agencies, to carry on this work. >> reporter: the real test of the summit's success will be whether nations continue their work on safeguarding their nuclear material without a nudge from the white house >>> north korea says it will continue its nuclear and ballistic weapons program. south korea says the north fired another short range missile on friday. a north korean official says